Comment 10 for bug 1547793

up-daemon-generated.c has this code:

1158 g_variant_new ("(o)",
1159 device));

(gdb) p device
$1 = (const gchar *) 0x555555588af2 "PowerOff"

which is indeed not a valid object path. This should certainly not crash with a segfault but trigger an assertion, so there's a glib bug as well.